WASHINGTON (Reuters) - A coalition of addiction experts,
physicians and others is urging U.S. health officials to reverse
course and block the launch of a powerful painkiller called
Zohydro, expected to hit the market next month.

The opioid drug, manufactured by Zogenix Inc, contains a
potent amount of an active ingredient that could be lethal to
new patients and children and is not safer than other current
pain drugs, the groups told the Food and Drug Administration.

"Someone unaccustomed to taking opioids could suffer a fatal
overdose from just two capsules. A single capsule could be fatal
if swallowed by a child," they wrote in a petition to FDA
Commissioner Margaret Hamburg, dated Wednesday.

In December, attorneys general from 28 states also urged the
FDA to reconsider its approval of the drug.

Zogenix, in a statement, said it was confident in the FDA's
approval of the drug, which will be "subject to stricter
prescribing and dispensing rules." The company has said it plans
to start selling the drug in early March.

The latest petition came as the United States grapples with
an epidemic of prescription drug abuse, especially involving
powerful opioid pain medications. Opioids are a class of drugs
that includes morphine, codeine and oxycodone as well as
hydrocodone.

Nearly 5 million people in the United States ages 12 and
older abuse pain drugs, outpacing sedatives, stimulants and
other abused medications, according to a 2012 U.S. government
survey.

The FDA, which has launched its own efforts aimed at curbing
abuse of pain-killing medications, approved Zohydro last year
despite earlier concerns from a panel of FDA outside advisers
worried about addiction risks.

The FDA advisers echoed the concerns of public health
experts, law enforcement and others, who pointed to the drug's
delivery system and say they are worried about the potential for
Zohydro to be crushed or injected.

Zohydro can contain as much as 10 times the amount of the
narcotic hydrocodone as other painkillers such as AbbVie Inc's
Vicodin or UCB Inc's Lortab, advocates said in their petition.

"Zohydro is not safer," they wrote.

Both Vicodin and Lortab also contain the pain-killing
ingredient acetaminophen. Zohydro does not.

FDA officials have said they are working to balance public
health worries about opioid addiction with access to the drugs
for patients seeking pain relief. The FDA has said Zohydro's
benefits outweigh its risks.

FDA spokeswoman Morgan Liscinsky said the agency would
review the group's letter.

The petition was signed by 42 supporters, including
representatives of advocacy groups such as Public Citizen as
well as physicians and community addiction treatment providers.